A boarding school has made payouts to two teachers who claimed they were made to work 120-hour weeks and were left "shattered by sleep deprivation".
Two "house parents" at the boarding house at Edge Grove School in Hertfordshire said they were made to work 24 hours a day for at least five days a week without sufficient breaks.
They complained that a typical day at the co-educational 3-13 school included a wake-up call and breakfast for pupils at 7am, lessons all day, supper and dorm supervision until 9.30pm and on-call duties overnight.
The school, which charges upper school boarders more than #163;19,000 a year in fees, maintains it did not overwork the two members of staff, and says it agreed to make the payments of #163;10,000 and #163;3,000 to avoid incurring costs from a tribunal case.
"We were satisfied that the employees had the opportunity to take adequate rest during days off and the long holidays, but we took the pragmatic decision to settle the matter before a hearing," said bursar Martin Sims in a statement to TES.
He added that the welfare and safety of pupils was of the "utmost importance" in the school's staffing arrangements.
"The school remains committed to ensuring that their staff have adequate break periods when at work," he said.
The case is just the latest involving teachers working in boarding schools complaining about excessive hours. In 2007, assistant housemistress Barbara White was awarded #163;12,000 by Malvern College in Worcestershire because she was contracted to work more than 121 hours a week for just over #163;15,000 a year, which amounted to less than the minimum wage at the time.
One of the members of staff to receive a payout in the Edge Grove case, French teacher Matthieu Lefebvre, said: "The school just wasn't interested when we said we couldn't continue to work without breaks because we were so shattered due to sleep deprivation that we couldn't function properly. It was totally unreasonable. I felt exploited. I had to give up teaching, which I loved, after 10 years, to regain some sanity in my life.
"No one should be expected to regularly work 120 hours a week without a break - it's just not feasible."
Mr Lefebvre has since moved to Australia to work as a risk management consultant.
Education union the Association of Teachers and Lecturers (ATL), which represented the teachers, says staff working in boarding schools are entitled to the equivalent of 11 consecutive hours' rest between work days, a 24-hour break if they work for seven days or a 48-hour break when they work for 14 days.
John Richardson, ATL's national official for independent schools, said: "This is a truly appalling case of exploitation, which endangered the health of our members, who were permanently exhausted. The two members of staff were also likely to have been less effective teachers as a result of their fatigue.
"We are concerned that there is a culture of working excessively long hours without proper breaks in independent schools, especially boarding schools... We call on all independent school employers to ensure that their staff have sufficient breaks and time off."
Kehinde Adeogun, ATL's solicitor, said: "We are delighted to have achieved the payout for our members, and warn other schools that we will challenge them if we find they have been treating staff in a similar way."
One of the members worked at the school for 20 months, the other for three months from September to November 2011.